Re: [Qemu-devel] [PATCH for-2.12 09/12] vhdx: Require power-of-two block size on create

[Eric Blake]

On 03/20/2018 12:36 PM, Kevin Wolf wrote:
> Images with a non-power-of-two block size are invalid and cannot be
> opened. Reject such block sizes when creating an image.
>
> Signed-off-by: Kevin Wolf <address@hidden>
> ---
>   block/vhdx.c | 4 ++++
>   1 file changed, 4 insertions(+)

Reviewed-by: Eric Blake <address@hidden>

> diff --git a/block/vhdx.c b/block/vhdx.c
> index f1b97f4b49..ca211a3196 100644
> --- a/block/vhdx.c
> +++ b/block/vhdx.c
> @@ -1877,6 +1877,10 @@ static int coroutine_fn 
> vhdx_co_create(BlockdevCreateOptions *opts,
>           error_setg_errno(errp, EINVAL, "Block size must be a multiple of 1 
> MB");
>           return -EINVAL;
>       }
> +    if (!is_power_of_2(block_size)) {
> +        error_setg(errp, "Block size must be a power of two");
> +        return -EINVAL;
> +    }
>       if (block_size > VHDX_BLOCK_SIZE_MAX) {
>           error_setg_errno(errp, EINVAL, "Block size must not exceed %d",
>                            VHDX_BLOCK_SIZE_MAX);

--
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org